Iranian TV blames poor weather for crashRescuers trying to reach crash site in rainA helicopter carrying Iranian President Ebrahim Raisi and his foreign minister crashed on Sunday as it was crossing mountain terrain in heavy fog, an Iranian official told Reuters, and rescuers were struggling to reach the site of the incident.The official said the lives of Raisi and Foreign Minister Hossein Amirabdollahian were "at risk following the helicopter crash", which happened on the way back from a visit to the border with Azerbaijan in Iran's northwest."We are still hopeful but information coming from the crash site is very concerning," said the official, speaking on condition of anonymity.Iranian Supreme Leader Ayatollah Ali Khamenei sought to reassure Iranians, saying there would be no disruption to state affairs.Iranian state media said bad weather was the cause of the crash and was complicating rescue efforts. The chief of staff of Iran's army ordered all the resources of the army and the elite Revolutionary Guard to be put to use in search and rescue operations."It is dark and it has started raining, but the search continues. Rescue teams have reached the area ... however, the rain has created mud, making the search difficult," a local reporter told state TV.State TV had earlier stopped all its regular programming to show prayers being held for Raisi across the country and, in a corner of the screen, live coverage of rescue teams deployed on foot in the mountainous area in heavy fog.The rescue teams were expected to reach the probable site of the crash later on Sunday evening.Neighbouring countries expressed concern and offered assistance in any rescue. The White House said U.S. President Joe Biden had been briefed on reports about the crash. The European Union offered emergency satellite mapping technology to help Iran with the search.Raisi has been president of the Islamic Republic since 2021 when he succeeded the moderate Hassan Rouhani, for a term during which Iran has faced crisis and conflict.He took the reins of a country in the grip of a deep social crisis and an economy strained by US sanctions against Tehran over its contested nuclear programme.Iran saw a wave of mass protests triggered by the death in custody of Iranian-Kurdish woman Mahsa Amini in September 2022 after her arrest for allegedly flouting dress rules for women.In March 2023, regional rivals Iran and Saudi Arabia signed a surprise deal that restored diplomatic relations.The war in Gaza that broke out on October 7 sent regional tensions soaring again and a series of tit-for-tat escalations led to Tehran launching hundreds of missiles and rockets directly at Israel in April 2024.Raisi had been at the Azerbaijani border on Sunday to inaugurate the Qiz-Qalasi Dam, a joint project. Azerbaijan's President Ilham Aliyev, who said he had bid a "friendly farewell" to Raisi earlier in the day, offered assistance in the rescue.In a speech following Sunday's dam inauguration, Raisi emphasised Iran's support for Palestinians, a centrepiece of its foreign policy since the 1979 Islamic revolution."We believe that Palestine is the first issue of the Muslim world, and we are convinced that the people of Iran and Azerbaijan always support the people of Palestine and Gaza and hate the Zionist regime," said Raisi.Raisi, born in 1960 in northeast Iran's holy city of Mashhad, served as Tehran's prosecutor-general from 1989 to 1994, deputy chief of the Judicial Authority for a decade from 2004, and then national prosecutor-general in 2014.